Trosper et al. disclosed in their U.S. Pat. No. 3,878,635 a signalling device, such as the lighting of a bulb, which is actuated by a magnetic switch operated by a pulley system and can be utilized on a fishing rod. If such a signalling bulb is inferentially expected to be controlled by a hand-operating switch substituting the fishing-wire strained pulley system 7, the bulb can then be used as a signalling device. However, such a hand-operating switch must still be rotated or seesawly operated by the user, causing a slow signalling action especially not suitable for an emergency call for help.
The present inventor has found the shortcoming of a conventional bulb used for signalling purpose and invented the present miniature flashlight which is simply operated by touching an outer sleeve jacketed on its housing.